Access to Google's Gmail service appears to be disrupted in Iran just days before the country's presidential election.

Google said it has noticed a drop in connectivity to Gmail from the country. The connectivity drop appears to fall short of a complete block of Gmail services, but there may be significant disruptions for users in Iran, Google said.

On Tuesday, a group called "Iran News Update" said on Twitter that Gmail had been blocked in the country and VPN (virtual private network) connections were being disrupted.

Iranians are scheduled to go to the polls on Friday for the first round of the country's presidential election. A second round will be held on June 21 should no candidate succeed in getting more than 50 percent of the first-round vote. Six candidates are competing to replace President Mahmoud Ahmadinejad, who is stepping down because he has reached the limit of his presidential term.

Iran has a recent history of blocking and filtering access to Internet services and websites it deems offensive. The country has said several times that it's planning to launch a nationwide intranet service that would offer users access to approved domestic services and cut off most or all foreign websites. The only other country to restrict users in such a fashion is North Korea.

In 2009 after the last presidential election, mobile phone service in Tehran and access to Facebook and YouTube were blocked shortly before President Ahmadinejad went on state television to declare victory, according to several news reports from the time. The block of YouTube remains in place to this day.

Iran has also been accused of jamming international satellite television broadcasts into the country.

The country ranks 174th on Reporters Without Borders' press freedom index, putting it ahead of just Somalia, Syria, Turkmenistan, Eritrea and North Korea.